186 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Degeneration and Regeneration in Sponges.* — H. V. Wilson notes 

 that siliceous sponges in confinement give rise to small masses of un- 

 differentiated tissue, which in their turn are able to grow and differen- 

 fciate into perfect sponges. In a species of Stylotella the process as a 

 whole has been worked out. The oscula and pores close, the canal 

 system is in some degree suppressed, the sponge shrinks and becomes 

 like Spongilla in its winter state. It may subdivide into numerous 

 masses, which recover their differentiation in open water. In other cases 

 a large part of the sponge dies, but living fragments remain, which can 

 recover. Minute masses may occur over the general surface, or they 

 may be scattered throughout the body. These small remnants behave 

 like plasmodia ; they are aggregations of syncytial protoplasm studded 

 with nuclei. Wilson has showm that when suitably exposed in open water 

 they can form perfect sponges. This production of regenerative tissue 

 has been seen in Mkrociona, but only in Stylotella has the author directly 

 proved the regenerative power. Maas has described in degenerating 

 Sycons the formation of compact cords of cells showing amoeboid pheno- 

 mena. It may also be noted that in 1886 J. Arthur Thomson described 

 and figured what he called "regenerative capsules" in Spongelia pallescens, 

 without, however, following up their history. 



Antarctic Monaxonellids.f — R. ] Kirkpatrick reports on the 

 Monaxonellida brought home by the ' Discovery ' — a collection of 43 

 species, of which 24 are new. The following new genera are established 

 — Sigmaxinyssa, Cercidochela, and Hoplahithara. 



New Fresh-water Sponges from Calcutta.:}: — Nelson Annandale 

 describes the following new species — Spongilla proliferens, S. crassissinw, 

 Fphydatia indica, Trochospongilla latouchiana, and T. phillottiana. 



Protozoa. 



Studies on Radiolarians. — V. Haecker § gives a detailed account 

 of the structure and development of the skeleton in Ccelographidge, 

 with special reference to the highly differentiated condition seen in 

 Cozlogr •aphis antarctica. Thus the central capsule is inclosed in an 

 internal shell, which consists of two halves and is beset with small teeth 

 on the aboral margin on both sides. Each of the shell-halves bears a 

 high helmet-like galea elongated towards the oral side, and at the base 

 of the galea is drawn out into a tube or rhinocanna extending towards 

 the oral shell-margin. The Coelographidre are not separable from the 

 Ccelodendridas, and the sub-order Phseodendria is proposed. Within 

 this there are five sub-families, characterised by their skeletons. The 

 author deals with eight genera and seventeen species. 



W. Mielck || deals with Acanthometridse from New Pomerania, and 

 works out a notable simplification of the systematic relations. 



* Science, xxv. (1907) pp. 912-15. 

 t Ann. Nat. Hist., xx. (1907) pp. 271-91. 



X Journ. and Proc. Asiatic Soc. Bengal, iii. (1907) pp. 15-26 (7 figs.). 

 § Arch. Protistenk., ix. (1907) pp. 139-69 (20 figs.). 



|| Wiss. Meer. Abt. Kiel, No. 10 (1907) pp. 41-105 (5 pis. and 20 figs.). See also 

 Zool. Zentralbl., xiv. (1907) pp. 621-8. 



